The Rock Record

1. The Rock Record Preview • Multiple Choice • Short Response • Reading Skills • Interpreting Graphics

2. Multiple Choice • A scientist used radiometric dating during an investigation. The scientist used this method because he or she wanted to determine the • relative age of rocks. • absolute age of rocks. • climate of a past era. • fossil types in a rock.

3. Multiple Choice, continued • A scientist used radiometric dating during an investigation. The scientist used this method because he or she wanted to determine the • relative age of rocks. • absolute age of rocks. • climate of a past era. • fossil types in a rock.

4. Multiple Choice, continued 2. Fossils that provide direct evidence of the feeding habits of ancient animals are known as • coprolites • molds and casts • imprints • trace fossils

5. Multiple Choice, continued 2. Fossils that provide direct evidence of the feeding habits of ancient animals are known as • coprolites • molds and casts • imprints • trace fossils

6. Multiple Choice, continued 3. One way to estimate the absolute age of rock is • nonconformity • varve count • the law of superposition • the law of crosscutting relationships

7. Multiple Choice, continued 3. One way to estimate the absolute age of rock is • nonconformity • varve count • the law of superposition • the law of crosscutting relationships

8. Multiple Choice, continued 4. To be an index fossil, a fossil must • be present in rocks that are scattered over a small geographic area • contain remains of organisms that lived for a long period of geologic time • occur in small numbers within the rock layers • have features that clearly distinguish it from other fossils

9. Multiple Choice, continued 4. To be an index fossil, a fossil must • be present in rocks that are scattered over a small geographic area • contain remains of organisms that lived for a long period of geologic time • occur in small numbers within the rock layers • have features that clearly distinguish it from other fossils

10. Multiple Choice, continued • Which of the following statements best describes the relationship between the law of superposition and the principle of original horizontality? • Both describe the deposition of sediments in horizontal layers. • Both conclude that Earth is more than 100,000 years old. • Both indicate the absolute age of layers of rock. • Both recognize that the geologic processes in the past are the same as those at work now.

11. Multiple Choice, continued • Which of the following statements best describes the relationship between the law of superposition and the principle of original horizontality? • Both describe the deposition of sediments in horizontal layers. • Both conclude that Earth is more than 100,000 years old. • Both indicate the absolute age of layers of rock. • Both recognize that the geologic processes in the past are the same as those at work now.

12. Short Response • What is the name for a type of fossil that can be used to establish the age of rock? Index fossil

13. Reading Skills Read the passage below. Then, answer questions 7–10. Illinois Nodules Around three hundred million years ago, the region that is now Illinois had a very different climate. Swamps and marshes covered much of the area. Scientists estimate that no fewer than 500 species lived in this ancient environment. Today, the remains of these organisms are found preserved within structures known as nodules. Nodules are round or oblong structures that are usually composed of cemented sediments. Sometimes, these nodules contain the fossilized hard parts of plants and animals. The Illinois nodules are extremely rare because many contain finely detailed impressions of the soft parts of the organisms together with the hard parts. Because they are rare, these nodules are desired for their incredible scientific value and may be found in fossil collections around the world.

14. Reading Skills, continued 7. According to the passage above, which of the following statements about nodules is correct? • Nodules are rarely around or oblong. • Nodules are usually composed of cemented sediments. • Nodules are rarely found outside of Illinois. • Nodules will always contain fossils.

15. Reading Skills, continued 7. According to the passage above, which of the following statements about nodules is correct? • Nodules are rarely around or oblong. • Nodules are usually composed of cemented sediments. • Nodules are rarely found outside of Illinois. • Nodules will always contain fossils.

16. Reading Skills, continued 8. What is the most unusual feature of the nodules found in modern-day Illinois? • their bright coloration • the fact that they come in many more unusual shapes than other nodules • the fact that they contain both the soft and hard parts of animals • their extremely heavy weight

17. Reading Skills, continued 8. What is the most unusual feature of the nodules found in modern-day Illinois? • their bright coloration • the fact that they come in many more unusual shapes than other nodules • the fact that they contain both the soft and hard parts of animals • their extremely heavy weight

18. Reading Skills, continued 9. Which of the following statements can be inferred from the information in the passage? • Illinois nodules are sought by scientists. • Nodules can be purchased from the state. • Similar nodules can be found in nearby Iowa. • Nodules contain dinosaur fossils.

19. Reading Skills, continued 9. Which of the following statements can be inferred from the information in the passage? • Illinois nodules are sought by scientists. • Nodules can be purchased from the state. • Similar nodules can be found in nearby Iowa. • Nodules contain dinosaur fossils.

20. Reading Skills, continued • What might scientists learn from nodules that contain the soft and hard parts of an animal? Your answer should include the following points: Fossils that include the soft parts of animals are rare and may include impressions of organs or muscles; scientists can use these animal parts to learn more about the internal structures and body systems of ancient animals; scientists can compare the internal systems of ancient animals to the internal systems of modern animals in order to see how different animals and body systems have changed over time.

21. Interpreting Graphics Use the figure below to answer question 11. The graph shows the rate of radioactive decay.

22. Interpreting Graphics, continued • How many half-lives have passed when the number of daughter atoms is approximately three times the number of parent atoms? • one • two • three • four a waning moon.

23. Interpreting Graphics, continued • How many half-lives have passed when the number of daughter atoms is approximately three times the number of parent atoms? • one • two • three • four a waning moon.

24. Interpreting Graphics, continued The diagram below shows crosscutting taking place in layers of rock. Use this diagram to answers questions 12 and 13.

25. Interpreting Graphics, continued • Which of the letter combinations below belong to the same layer of rock before the fault disrupted the layer? • C and D • C and F • G and I • G and F

26. Interpreting Graphics, continued • Which of the letter combinations below belong to the same layer of rock before the fault disrupted the layer? • C and D • C and F • G and I • G and F

27. Interpreting Graphics, continued • Which is older, structure B or structure X? Explain your answer. What structure shown on the diagram is the youngest? Your answer should include the following points: Structure X is a simple fault, which by definition is younger than the rock it cuts through; rock layer B must have formed before fault X occurred; rock layer A is the youngest structure shown on the diagram. The unbroken layer on top is the youngest structure shown in the diagram. This layer must have formed after the fault, it would be broken in the same way that the other rock layers were broken.